I am trying to benchmark my ubuntu server and got to know that the
Phoronix Test Suite
Thanks to @Michal's comment, I figured it out that the benchmarking tests were single threaded and hence utilized only one core.
I tried running the same tests on a 2 and 8 core machines and I got
MAX CPU usage to roughly ~50% and ~12.5%
To check the multi-core performance we need to find other alternatives like